04 silverado stuck in 4HI

I have an 04 silverado, and I am stuck in 4wd. I have the push button option
and the light is telling me im in 2wd but I know without a doubt that im still in
4HI. Every now and then my lights will move from 2HI to auto 4 and back to
2Hi while driving down the road, but now none of my buttons will work. I have
pushed the 4HI 4LO 2HI and Auto 4 buttons but no lighting nor engaging takes
place, put it in nuetreal and reverse ect.. it still says im in 2wd. I cant switch
out of 2wd on my push button, but Im still driving in 4HI. I also have what
sounds like a ticking noise coming from under my truck which leads me to
believe it may be my transfer case. Another problem is I sometimes hear a
grinding noise in my front end when it says im in auto 4... any thoughts?